Powder or granular fly-ash was transported to the hopper by the belt conveyor or bucket elevator, and then enter into the feed end through the feeding tube by the hopper feeder. Slope of the feeding pipe must be greater than the natural angle of material so that the materials can flow into the sand dryer. Dryer cylinder forms a slightly tilted with the horizontal. Material was added from the higher to form reflux with the heat carrier entered from low-end. Sometimes, heat carrier flows into the cylinder together with the material. With the rotating of drum, material run to the lower end by gravity. In the moving process, wet materials obtain the heat input of heat carrier directly and indirectly to be dried, then, the finished materials are sent out by belt conveyor or screw conveyor.